Automated emergency call response systems in vehicles respond to a crash event by automatically notifying emergency response personnel such as police, fire departments, etc. Generally, the automated response system is triggered by the activation of the vehicle supplemental restraint (air bag) system. Prior art Original Equipment Manufacturer (OEM) systems incorporate a connection to either the vehicle OEM electrical bus or a direct connection to the air bag system itself to allow status monitoring of the air bag system in normal operation and notification to an emergency communication system in the event an air bag is deployed.
In the aftermarket vehicle situation, the many different types of vehicle electrical bus configurations and air bag systems precludes the safe and effective connection of an automated emergency call response system to provide the monitoring function. Disadvantages of prior art after market devices include accidental air bag deployment during installation and testing, intermittent connections, accidental damage to the air bag system, and the myriad of OEM electrical buses, which makes standardization of such a device difficult.
Prior art after market devices monitor the vehicle passenger compartment for a single acoustic frequency indicative of air bag deployment along with direct feedback from an accelerometer to indicate that the vehicle as been in an accident and to summon emergency aid. This prior art system has the disadvantage of requiring feedback from an accelerometer due to the monitoring of only a single frequency or impulse to indicate air bag deployment, without which can lead to false alarms and erroneous calls for emergency aid. The use of an accelerometer has the further disadvantage of the air bag detection system requiring feedback from an external device, which adds complexity and cost to the system.
Accordingly, there is a significant need for a method for an air bag deployment sensing apparatus and method that overcomes the deficiencies of the prior art outlined above.